I am very confused at the moment as i'm from the UK and have a set of instructions from the USA for a project I am trying to copy but the screw sizing used is in the American format and don't seem to be available here or are called something different!

I am trying to find a UK equivalent of a 1/4″-20 x 3″ round head slotted machine screw (I only need 3!) and their associated jam nut however upon searching for machine screws in the UK, I get them listed in the format M2 x 20, M6 x 50, A2 x something etc. These mean little to me. There doesn't seem to be a metric equivalent.

Can anyone here tell me what the screw I want is called in the UK (metric) format?

I would be very grateful.

joed

06-02-2010 06:46 PM

1/4 inch coverts to 64 mm. 3" converts to 7.62cm. I think that would be about an M6 x 8.

High Gear

06-02-2010 06:57 PM

Hey finally something I'm good at ( long time toolmaker)

A 1/4-20 x 3" ...

.= .250 thousands diameter by 20 threads per inch by 3 inches long

There is no direct equivalent but a

M6 X 1 x 75 may work although its a little undersize in diameter and that your going though a clearence hole and not trying to match with SAE threads